/Engine/Source/Editor/EditorFramework/Public/Viewports/InViewportUIDragOperation.h
Create this Drag and Drop Content
a new FDockingDragOperation
static [TSharedRef](API\Runtime\Core\Templates\TSharedRef)< [FInViewportUIDragOperation](API\Editor\EditorFramework\Viewports\FInViewportUIDragOperation) > New ( const [TSharedRef](API\Runtime\Core\Templates\TSharedRef)< class [SWidget](API\Runtime\SlateCore\Widgets\SWidget) > & InUIToBeDragged, const FVector2D InDecoratorOffset, const FVector2D & OwnerAreaSize, FOnInViewportUIDropped & InDropDelegate )